fix build errors

src/librssguard/gui/mediaplayer/libmpv/qthelper.h

@@ -150,7 +150,11 @@ namespace mpv {
           // "QVariant::Type(obsolete), the return value should be interpreted
           // as QMetaType::Type."
           // So a cast really seems to be needed to avoid warnings (urgh).
+#if QT_VERSION_MAJOR == 5
+          return v.type() == static_cast<int>(t);
+#else
           return v.typeId() == static_cast<int>(t);
+#endif
         }
         void set(mpv_node* dst, const QVariant& src) {
           if (test_type(src, QMetaType::QString)) {

src/librssguard/gui/mediaplayer/qtmultimedia/qtmultimediabackend.cpp

@@ -174,12 +174,48 @@ void QtMultimediaBackend::setVolume(int volume) {
 #else
   m_player->setVolume(volume);
 #endif
+
+  emit volumeChanged(volume);
 }
 
 void QtMultimediaBackend::setPosition(int position) {
   m_player->setPosition(convertSliderProgress(position));
 }
 
+void QtMultimediaBackend::setFullscreen(bool fullscreen) {
+  Q_UNUSED(fullscreen)
+  // No extra work needed here.
+}
+
+void QtMultimediaBackend::setMuted(bool muted) {
+  // This backend audio class does not support muting on Qt 5, so we emulate
+  // muting by seting volume to 0;
+  if (muted) {
+    // Remember volume and mute.
+#if QT_VERSION_MAJOR == 6
+    m_volume = convertToSliderVolume(m_player->audioOutput()->volume());
+#else
+    m_volume = m_player->volume();
+#endif
+
+#if QT_VERSION_MAJOR == 6
+    m_player->audioOutput()->setVolume(convertSliderVolume(0));
+#else
+    m_player->setVolume(0);
+#endif
+  }
+  else {
+    // Unmute.
+#if QT_VERSION_MAJOR == 6
+    m_player->audioOutput()->setVolume(convertSliderVolume(m_volume));
+#else
+    m_player->setVolume(m_volume);
+#endif
+  }
+
+  emit mutedChanged(muted);
+}
+
 QUrl QtMultimediaBackend::url() const {
   return
 #if QT_VERSION_MAJOR == 6
@@ -246,3 +282,7 @@ void QtMultimediaBackend::onPlaybackStateChanged(QMediaPlayer::PLAYBACK_STATE st
 void QtMultimediaBackend::onSeekableChanged(bool seekable) {
   emit seekableChanged(seekable);
 }
+
+int QtMultimediaBackend::convertToSliderVolume(float volume) const {
+  return volume * 100;
+}

src/librssguard/gui/mediaplayer/qtmultimedia/qtmultimediabackend.h

@@ -38,9 +38,12 @@ class QtMultimediaBackend : public PlayerBackend {
     virtual void playPause();
     virtual void pause();
     virtual void stop();
+
     virtual void setPlaybackSpeed(int speed);
     virtual void setVolume(int volume);
     virtual void setPosition(int position);
+    virtual void setFullscreen(bool fullscreen);
+    virtual void setMuted(bool muted);
 
   private slots:
     void onPlaybackRateChanged(qreal speed);
@@ -54,6 +57,7 @@ class QtMultimediaBackend : public PlayerBackend {
     void onSeekableChanged(bool seekable);
 
   private:
+    int convertToSliderVolume(float volume) const;
     float convertSliderVolume(int slider_volume) const;
     qint64 convertSliderProgress(int slider_progress) const;
     int convertToSliderProgress(qint64 player_progress) const;
@@ -71,6 +75,7 @@ class QtMultimediaBackend : public PlayerBackend {
 
     QMediaPlayer* m_player;
     QVideoWidget* m_video;
+    int m_volume;
 };
 
 #endif // QTMULTIMEDIABACKEND_H

src/librssguard/gui/settings/settingsmediaplayer.cpp

@@ -17,14 +17,14 @@ void SettingsMediaPlayer::loadSettings() {
   onBeginLoadSettings();
 
 #if defined(ENABLE_MEDIAPLAYER_LIBMPV)
-  m_ui.m_txtBackend->setText(QSL("QtMultimedia"));
+  m_ui.m_txtBackend->setText(QSL("libmpv"));
   m_ui.m_helpInfo->setHelpText(tr("You use modern libmpv-based media player backend with API version %1.")
                                  .arg(mpv_client_api_version()),
                                false);
 #elif defined(ENABLE_MEDIAPLAYER_QTMULTIMEDIA)
-  m_ui.m_txtBackend->setText(QSL("libmpv"));
+  m_ui.m_txtBackend->setText(QSL("QtMultimedia"));
   m_ui.m_helpInfo->setHelpText(tr("You use lightweight QtMultimedia-based media player backend. If some videos do not "
-                                  "play, then you likely need to install some codec pack."),
+                                  "play, then you likely need to install some codecs."),
                                false);
 #else
   m_ui.m_txtBackend->setText(tr("no backend installed"));